When you try to apply managed mailbox folder policy to a mailbox using set-mailbox, you would run a command like this:
set-mailbox -identity mailboxA -ManagedFolderMailboxPolicy "MFPolicy"
This would result in a confirmation prompt
Confirm <br />Are you sure you want to perform this action? <br />...
To avoid the prompt, you instead run command
set-mailbox -identity mailboxA -ManagedFolderMailboxPolicy "MFPolicy" –confirm:$false
However, you will get prompted again with the following:
Confirm <br />When assigning a managed folder mailbox policy…
To put it in perspective, the first confirmation prompt is for set-mailbox operation. The second confirmation prompt is for applying Managed Folder Policy. Whenever Managed Folder Policy is applied, it impacts legacy Outlook client functionality. Which explains why additional confirmation is needed.
So, how can you tell the shell not to ask you for confirmation as you know what you are doing or you don’t care if it breaks 
?
Type this:
set-mailbox -identity mailboxA -ManagedFolderMailboxPolicy "MFPolicy" -ManagedFolderMailboxPolicyAllowed -Confirm:$false
you can now tell the computer who is the boss. 
